1. Field of the Invention
The present invention relates to a method of adding a mixing material and/or a mixing agent to provide a cement admixture such as concrete, mortar, cement paste, and a package of a mixing material to be used therefor.
2. Description of the Related Art
Currently, as a mixing material, there are employed a superplasticizer, an air-entraining agent, an air-entraining water-reducing agent, a super air-entraining water-reducing agent, a setting accelerating agent, a setting retarder, a separation reducing agent, a rust or corrosion inhibitor, an expanding agent, a polymer mixing agent, a shrinkage reducing agent, a coloring agent, or a reinforcing material. These materials are added to predetermined amounts of cement mixing materials corresponding to the standard recipe of cement formulations such as concrete, mortar, or cement paste. Particularly, with regard to a superplasticizer, after a visual measurement of the slump of the concrete transported by a truck agitator by an expert sent from a manufacturer, the amount of superplasticizer to be thrown must be determined before metering and throwing from a drum can or an atron can, or it must be thrown by an automatic metering pump, and this is cumbersome.
When using a mixing material, the mixing material may leak or drip during the metering and throwing, and thus will contaminate the working site and cause a deterioration of the working environment. Further, the used packaging materials such as drum cans require much time for cleaning, as well as time required for the maintenance and storage of remaining mixing materials, metering instruments and metering pumps.
Accordingly, the present inventors proposed an addition of a superplasticizer agent to a cement admixture by throwing a package including a suplasticizer into a truck agitator (Japanese Patent Application No. 2-46973).